Sorry it’s taken me so long to respond. Your message got lost in a VERY long list of spam comments.

I usually try to use the phrase “work until 5 sts to the end” or something similar when the type of stitch can vary, but sometimes I forget to do that and use the word “knit” in its generic sense, rather than its specific meaning. If it’s a purl row, then yes, you should be purling. Substitute the phrase “work to 5 sts to the end,” and the meaning should be clear: you’re working in stockinette, so knit the sts that present as knits and purl sts that present as purls.